Pulsed neutron diffraction measurements of nanoscale ceria powder revealed new structural features which appeared to be closely related to the material’s O-storage characteristics. The results of a pair-distribution function analysis, and of Rietveld refinement of the neutron diffraction data, indicated the presence of interstitial O defects in the octahedral sites of the fluorite structure. The defects were found to disappear during high-temperature heat-treatment. It was suggested that these weakly-bound interstitial O defects facilitated O mobility, and enhanced the O-storage characteristics.

Structural Defects in a Nano-Scale Powder of CeO2 Studied by Pulsed Neutron Diffraction. E.Mamontov, T.Egami: Journal of the Physics and Chemistry of Solids, 2000, 61[8], 1345-56